1. Field of the Invention
The present invention relates to a packaging bag in which a shaping member for keeping a bag shape to a hexahedron shape is disposed inside a bag body.
2. Related Art
Conventionally, there is known a packaging bag in which a fastener is attached to an inner surface of an opening portion of a bag body for the purpose of re-sealing the opening portion after once opened. In recent years, to such packaging bag, it is desired as an increased demand to accommodate a content in the packaging bag without deforming or damaging the outer appearance thereof. The applicant of the subject patent application has been studying and developing so as to satisfy such desire and provided technology which was disclosed in the Japanese Patent Laid-open (Unexamined) Publication No. 2001-322187.
The invention disclosed in the this patent publication relates to a packaging bag provided with a bag body formed of a film material, and a shaping member is disposed inside the bag body to keep the outer appearance of the bag body in shape of hexahedron. In a case of forming such packaging bag, a sheet of film material is bent at its central portion, and both side edge portions of the bent sheet are then bonded.
Flat surface portions and side surface portions of the packaging bag are formed by applying tensions to the film material forming the bag body by the shaping member disposed therein. On the other hand, an upper portion of the packaging bag is formed by bending, toward the central portion, portions corresponding to the respective flat surface portions in a portion protruding over an upper end portion of the shaping member, folding back, toward a bottom surface side, triangular portions corresponding to the respective side surface portions and sealing the folded portions to the side surface portions. The bottom surface portion of the packaging bag is formed by bending the triangular protruded portions formed on both sides of the bottom surface portion toward the central side of the packaging bag and then sealing the bent portion to the outer side surface of the bottom surface portion.
The packaging bag disclosed in the above publication has a subject feature of capable of accommodating a content in the bag body without deforming the shape of the content by keeping the outer shape or appearance of the bag body to the hexahedron shape by using the shaping member.
The applicant has been studied and developed such packaging bag after the disclosure of such invention as in the above publication so as to improve productivity, to improve inner-content protective performance, to reduce possibility of the deformation of the shape, to reduce possibility of breakage of packaging bag and so on.